Driving connection mechanism



APiilW5J9'54' M. E. HARDY DRIVING CONNECTION MECHANISM Filed Feb. 5. 1952 FIG.1

INVENTOR. MAURICE E. HARDY HIS ATTORNEY.

Patented Apr. 6, 1954 UNITED STATES PATENT orrlcs muvmo CONNECTION MECHANISM Maurice E. Hardy, Chicago, Ill., assignor to Zenith Radio Corporation, a corporation of Illinois Application February 5, 1952, Serial No. 270,056

3 Claims. (Cl. 74-200) flexibility with respect to possible future record speeds and adjustability to satisfy the listeners personal preference as to the manner of reproduction. One type of continuously variable speed driving system is disclosed in the copending application of Ralph A. Mullaney, Serial No.

to the same assignee as the present invention.

The Mullaney arrangement utilizes a driving disc positioned parallel to the turntable and urged along its axis toward the turntable, and includes a mechanism for completing a driving connection between the turntable and'the driving disc. This mechanism comprises an idler wheel interposed" between the driving disc and the turntable and a movable carriage supporting the idler wheel. Ideally, the carriage should be free to move laterally along a line between the axes of rotation of g the disc and the turntable and should permit substantially linear vertical movement of the idler wheel. While the described arrangement meets the desired operating characteristics and has been employed commercially with considerable success, it has been found that improvements may be made in its mechanical features.

It is an object of this invention, therefore, t provide a driving connection mechanism of the type described but having improved mechanical" able-speed driving connection between the turn.-

table and the disc is required. In accordance with the invention, this mechanism comprisesan' 1 idler wheel interposed between the disc andthe 2 turntable to effect a mechanical connection between them. An elongated stationary shaft is provided, and a movable carriage is .positioned between the idler wheel and the shaft, the carriage supporting the idler wheel at one end thereof. At least one hook-shaped projection extends.

from the opposite end of the carriage in encom passing engagement with the shaft, and a resilient extension member also projects from the aforesaid opposite end of the carriage, engaging the shaft in diametrical opposition to the engagement of the hook-shaped projection. The engagement of the hook-shaped projection and the resilient extension member with the stationary shaft completes a mechanical linkage between the shaft and the carriage for guiding lateral movement of the carriage parallel to the shaft to adjust the speed of the turntable and for permitting pivotal movement of the carriage with re pect to the shaft.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. invention itself, both as to its organization and manner of operation, together with further ob- Y jects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawing in which like parts are indicated by like numerals in the different figures, and in which:

Figure 1 is a plan view of a phonograph including a turntable driving system embodying the present invention, a portion of the turntable being broken away to reveal the driving system;

Figure 2 is a sectional view, partially schematic, taken along line 2-4 of Figure 1; and I Figure 3 is a perspective detail view of a portion of'Figure 1.

The phonograph represented in Figure -1 iii-' clu'cles a-turntable I ll supported-for rotation upon a mounting base II. A central spindle l2 extends upwardly from the turntable and a record disc l3, shown in dash-dot outline, is centered thereby on the turntable. A tone arm [4 is pivotally aflixed at one end of a conventional tonearm shaft supported on base II and carries a stylus (not shown) engageable with the grooves of record disc I3. A driving disc I5 is positioned below and in parallel relation to turntable l0, and a mechanism to be described more fully hereinafter and including an idler wheel is interposed between the driving disc and turntable I completes a variable speed driving connection therebetween. As more clearly shownin Figure The present fixed to a. ;sub.-ca'se 22,-esuspendedzfrom based I... which also supports a driving motor23 of the constant speed type. A driving connection between disc 15 and motor 23 is effected through a" motor shaft 24 which is maintained infrictional.

contact with the periphery of disc !5.'

The turntable driving system:rassthussfarsde scribed is generally similar to that'of the-above- 4 identified Mullaney application. and reference.

may be had thereto for mechanical details 4 to the shaft. The use of two hook-shaped projections 25 is strictly a matter of choice determined by considerations of convenience of assembly; it will be obvious to those skilled in the art that a single such member wide enough to limit the lateral movement of carriage H to a path parallel to shaft 26, will suffice. Resilient extension 28 maintains the shaft and carriage in.==positiveeengagementz "The described linkage of carriage I! and shaftzt guides'the movement of the carriage laterally parallel to the shaft While still permitting the carriage to pivot freelyabout. the-.-shaf.t-. One of the chief advantages of the system is the elimination of speed irregularities. and yibration'due to possible irregularities omitted from the instant drawing for purposes.

of simplification. More particular consideration will.-1-now-be-.given .to the-mechanism, including idler-wwheel -.l t, which constructed in accord--- ance-With the: subject invention- Idler wheel. .5 t of this mechanism -.is .rotatably.

mounted on .one. end .of .a movable carriage .H. which'iis associated with mounting base. H as clearly'shown in the perspective .view Figure 3.

Asjindicated in that figure;.carriage i l terminates infa pair of hook-shaped projections '25 extendingjfronrthe end' ofthe carriage opposite that which supports idler wheel it. These hookshaped projectionsfls are in encompassing engagement with an elongated stationary "shaft 25* intidia'metrical opposition "to: th'ewengagement of suchthoolnshaped members" 'AnJactuating arm- 29"projects'tfromithe carriageiparallel to. theaxis a? of shaft 25 and has a slot SZfOrisecuring a .pin".

33-.-=fixedltora speed-adjusting lever 34?- Lever 34 is-:pivotally mounted on: base I 5 1: by a pivot pint'ilFigure l)..-

Inoperation, driving disc" l5 rotates at a.

constant speed about shaft l8; driving-impetus for-the'disc beingsupplied :by motor-23 through I the-frictional contact. between disc A 5 .and I motor shaft-24.- The disc-l5 isurged .intocontactwith idler wheel l5 byspring lS-which also: urges idlerwheel alt-into -.driving contact: withturntable Hl..-- Thus the rotary motion imparted ,to driving disc Ma ay motor 23 is transmitted to turn-- tablelll throughidler wheelHlE-N Whenchange in the: rotary speed of turntable. .18 -isdesirable,

the: :position of :lever mays be. changed, the

movement thereofbeing impartedtomovable carriage it through the. linkage supplied (by. pin

33 and slot 32 of arm 29. Lateral movement of theicarriage alters thepositionof .idlenwheel i5 withirespectfto the axes .of rotation .of driving disc 15 .and turntable It. If the idler wheel. is..dis.-

placed toward the axis of .disc E5, the turntable.

speed .is reduced, whereas displacement inthe opposite direction increases the turntable speed.

lnQorder that the system may operate efficient ly,. it is desirable for carriage H to effect lateral movementof. the idler wheel 16 substantially in.

a path described by a plane including the .axes

of rotationof disc l5 and turntable .i 0. The shaft 26, which guides this lateral.movement,.istherm fore mounted parallel to a plane including those axes .of ,rotation. .The -.h ook-:shapedmembers .25

ma-i z it aiiriz sufiiciently close contact with the;shaft-..

toalimit'lateralwmovement to -.adirectlonparallel 1.75

inzthe'frictionalsurfaces of disc I5 and turntable 10.....Compensationfor such surface variations is effected through the resilient bias supplied by resilient member l9 urging disc l5 into driving contact with turntable H3 through idler wheel I65. To'makethis' ironing-out action-=effective, idler wheel-:16 mustber'free to move along a sub-z stantia-llyjlinear vertical I path,- since any restricez l tion on such movement effectively reduces-the;

advantage achieved. through use of thewrcsilient biasing. structure.- The length of -.carriage l .1 -'iS:"- therefore madesuiiiciently. greattolimit vertical movement of :idler wheel '16 to a substantially linear path.

The-idler wheel-.16, carriagel'l, and the-car riage mounting arrangement. comprising shaft 26,-.hoolr-shaped projections.25,;and resilient ex? tension; 28,-.provide an improved; drivinggccn'v nection mechanism which permits-unrestricted substantially linear vertical motion. of idler. wheels.

r of the-"carriage structure before engagement. with "the stationary shaft 26;-

While a particular v embodiment: of: the "present invention :has' been-shown and described, itzwillz. be obvious tothose skilled-in the .art'thatchanges: andemodifieations maybe madewithout departing-itfrom"'the invention 'in its :broader aspects; and; therefore; the aim in'the appended-claims is-'to*cover all such changes and modifications as fall within-the true'spirit and scope oftthe invention:

Iclaim:

1; ma driving system for a phonograph turntable'including a driving disc' positioned parallel to said turntable and urged along its :axis toward usaid turntable, .a 'mechanism for completing variable-speed driving: connection. between. said turntable and "said disc comprising: an"idler'i' wheel interposed between said disc and said turntable to eifect' a mechanical connection therebetween; an elongated stationaryshaftya chanical linkage between said shaft and said carriage for guiding lateral movement of said carriage parallel to said shaft to adjust the speed of said turntable and for permitting pivotal movement of said carriage with respect to said shaft.

2. In a driving system for a phonograph turntable including a driving disc positioned parallel to said turntable and urged along its axis toward said turn table, a mechanism for completing a variable-speed driving connection between said turntable and said disc comprising: an idler wheel interposed between said disc and said turntable to effect a mechanical connection therebetween; an elongated stationary shaft; a movable carriage, positioned between said idler wheel and said shaft, one end thereof supporting said idler wheel; a pair of hook-shaped members extending from the opposite end of said carriage in partially encompassing engagement with said shaft; and a resilient extension member on said carriage projecting between said hook-shaped members and engaging said shaft in diametrical opposition to the engagement of said hookshaped members to complete a mechanical linkage between said shaft and said carriage for guiding lateral movement of said carriage parallel to said shaft and for permitting pivotal movement of said carriage with respect to said shaft.

3. In a driving system for a phonograph turntable including a driving disc positioned parallel to said turntable and urged along its axis toward said turntable, a mechanism for completing a variable-speed driving connection between said turntable and said disc comprising: an idler wheel interposed between said disc and said turntable to effect a mechanical connection therebetween; an elongated stationary shaft substantially parallel to said turntable and to a plane including the axes of rotation of said disc and said turntable; a movable carriage, positioned between said idler wheel and said shaft, one end thereof supporting said idler wheel; a pair of hook-shaped members extending from the opposite end of said carriage in partially encompassing engagement with said shaft; and a resilient extension member projecting from said opposite end of said carriage and in engagement with said shaft in diametrical opposition to the engagement of said hook-shaped members to complete a mechanical linkage between said shaft and said carriage for guiding lateral movement of said carriage parallel to said shaft and for permitting pivotal movement of said carriage with respect to said shaft.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 520,626 Alberger May 29, 1894 617,738 Hale Jan. 17, 1899 837,828 Hasselquist et al. Dec. 4, 1906 1,814,381 Gross July 14, 1931 

